1. Field of the Invention
The present invention relates in general to data and signal processing and in particular to circuits and methods for power management in a processor-based system and systems using the same.
2. Description of the Related Art
The power loading of a data processing engine is often a time-dependent function of the software being run and/or the type of data being processed. For example, if the software is partitioned for batch processing, the current draw of the processing engine increases as instructions execution picks-up and decreases as instruction execution drops-off. Similarly, if data are processed in blocks, the current draw increases as each block is processed and decreases during the “quiet” time between blocks. As the load varies, so does the noise injection into the device substrate. Moreover, as the loading changes, signal edge rise and fall times vary as the current available for driving the corresponding capacitive loads varies, (especially for signals generated from the same voltage supply as the processor).
In almost all applications, the noise caused by a modulated load is undesirable, and in some cases can even be tolerated. In certain applications, however, such as audio decoding and encoding, this noise can significantly impact system performance and adversely affect the quality of the output experienced by the end-user.